New changelog entries:
* Fix detection of systemd to fix 'apache2ctl start' on sysv-init.
Closes: #852543
* Compile mod_bucketeer mod_case_filter mod_case_filter_in for benefit of
the test suite, but don't add *.load files because they don't have any
real-world use.
* Include the upstream test suite and a corresponding autopkgtest. This
is quite a hack but it may help quite a bit with security updates,
especially if stretch gets LTS support, too.

New changelog entries:
* Activate mod_reqtimeout in new installs and during updates from
before 2.4.25-2. It was wrongly not activated in new installs since
jessie. This made the default installation vulnerable to some DoS
attacks.
* Restart htcacheclean on updates and tighten dependency on apache2-utils
to ensure that apache2-utils cannot be upgraded without apache2.
Closes: #851122
* When running on systems with systemd, make 'apache2ctl start' invoke
systemctl instead. Otherwise systemd will think apache2 is not running
and ignore further commands like reload. Closes: #839227
* Avoid segfault in mpm_event if a signal is received too soon after start.
PR 60487
* Add test for some modules to be enabled.
* Remove mention of CVE-2016-5387 in 2.4.25-1 changelog. It was already
fixed in 2.4.23-2.

New changelog entries:
* Move the mod_ssl_openssl.h header and the dependency on libssl-dev to a
new package apache2-ssl-dev. Packages that interface with openssl
state from mod_ssl must build-depend on this new package.
This will help to disentangle the build-deps in the openssl transition.
Closes: #845033